Understanding disc image files
All the information stored on a disc can be converted into a single file called a disc image. That disc image file can then be used to reproduce the original disc. This is useful when you need to make several copies of the same disc but do not want to read from the source drive every time, or if you want to use your recorder to both read and write to your discs.
By having the disc image file stored on your hard drive, you free up the source disc for other uses. You can also send the disc image file across a network so other people can record their own copies.
By default, image files are created in the most compatible format and can be recognized by the .iso file name extension.